The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Brushed DC motors have been used to adjust a position of seats, mirrors or other components in automotive, aeronautical or other applications. For example, seat motors are used to move a seat assembly forward, backward, up and down. Seat motors are also used to adjust an angular position or tilt of a backrest portion relative to a seat portion of the seat assembly.
Some seat positioning systems store seat positions for drivers and/or passengers of the vehicle. Each of the stored seat positions may be associated with a recall button located on the seat assembly, door or other location. Alternately, a seat position may be associated with a key FOB. When one of the recall buttons is pressed or the key FOB is in the vicinity of the vehicle, the seat assembly automatically moves the seat assembly to the corresponding stored seat position. In order to reposition the seat assembly to the correct position, the seat positioning system needs to know a current position and a target position of each of the motors associated with the seat assembly.
In some applications, Hall Effect sensors are used to sense the positions of the motors. However, each of the motors needs to have a corresponding Hall Effect sensor and wiring. Some seat assemblies can have up to 14 motors. Therefore, the Hall Effect sensors and wiring may represent a relatively expensive component of the seat assembly.